<!DOCTYPE html>
<head>
    <script>

    /*var arr2 =new Array("a", "b", );
   
    arr2.push("c");
    
    alert(arr2);
    alert(arr2.length);
    alert(arr2.join("+"));
    alert(arr2[1]);
    */

    var now = new Date();
    console.log(now.getTime());
    //时间戳
    console.log(now.toLocaleTimeString());
    //当前时间
    
    var randomNum = Math.random();
    console.log(randomNum);
    var roundNum = Math.random();
    console.log(roundNum);
    var num1 = 3.1456;
    console.log(num1.toFixed(2));

    var wd = "北京冬奥会";
    var encodeWd1 =encodeURIComponent(wd)
    console.log(encodeWd1); 

    var decodeWd = "%E5%8C%97%E4%BA%AC%E5%86%AC%E5%A5%A5%E4%BC%9A";
    var str = decodeURIComponent(decodeWd);
    console.log("----" + str);

    var reg = new RegExp("^$")
    

    
    











    

    
    </script>
</head>
<body>
    
</body>